Statistical Concepts

Instructions for the
Serial Position Experiment

In this experiment, you can
experience one results from the study of memory, the serial position
effect. It has often been found that in recalling a list of
items, there is better recall for words from the beginning of the list
than those items in the middle of the list, the primacy effect.
If the recall is immediate, there is also better recall for items
at the end of the list, the recency effect. This experiment
should help illustrate this result. When you click on the link
below, you will be presented with the experiment setup screen. On
this screen will be the variables you can set to define your
condition. Here is a list of the variables and their settings

Variable

Settings

Stimulus Type

One of four types of stimuli can be used
currently (long words-7-10 letters, short words-3-4 letters, two digit
numbers, 4 digit numbers)

Number of times list is repeated

Each conditions will be repeated this
number of times in a row.

Number of items in list

The number of items to be remembered. From 2
to 9.

Duration of each item

The time duration which a word/math
problem set are presented (1 to 30 seconds)

Time before recognition

Delay between the end of the list and the
beginning of the recognition test (0 to 1800)

Time for Recognition

Time for the recognition task (5 to 120
seconds)

Font Size

The size of the letters that are
presented (from 12 to 64 point)

Duration of Fixation Target before Block

The time there is a fixation marker over
the location of the mathematical problem at the beginning of each block (0
to 20 sec)

Word Position

Adjust the relative height and horizontal
postion of the word.

After you have finished making your settings, press the Done button at the
bottom of the screen. The serial position experiment screen will then be presented.
A start bar will be at the top of the screen at every trial and instructions will be in the
center of the screen.

Press the space bar to begin the experiment.
The words will then be displayed one at a time in the position you have
selected.
At the end of the list and after the set delay, the words presented with an equal number of distracters
will be presented at the top of the screen in buttons. Click on the
buttons of the words you recognize. When you click the word will fade.
You will only be allowed to click on the number of buttons equaling the number
of words in the list.

At the end of the experiment your results
will be presented. For each condition you run, you will be given
the type of words presented, the overall accuracy for remembering those
words and also the proportion of words recalled for each position in
the list. You should recall more items at the beginning of the
list. If you do immediate recall you should also recall the last
items more than the items in middle of the list. This is a draft
experiment so expect modifications, but they will be coming slowly.s